Belfry Bulletin

Search Our Site

Article Index

 

Plantation Stream

(Is it a misnomer?)

by Bryan Ellis.

Throughout this article the following names are used for streams.  Main Stream - the stream flowing through St. Cuthbert's Swallet from the choke to the duck via Sewer Passage.  Plantation Stream - the tributary joining the Main Stream at Plantation Junction in the cave.  St. Cuthbert's Stream - the surface stream sinking in the large depression by the cave entrance.  Plantation Swallet Stream - the surface stream sinking in Plantation Swallet.

During the original exploration of St. Cuthbert's Swallet, a large tributary was found to join the Main Stream at the Eastern end of Sewer Passage; a tributary producing more water than the Main Stream in fact.  The only swallet known in the area of sufficient size was Plantation Swallet and therefore the tributary in the cave was called plantation Stream, but not without a certain amount of misgiving.  Because of the possibility of pollution, and the later agreement between the club and the owners of the cave, the water could not be contaminated by chemicals in sufficient quantity to prove the connection.  Don Coase was against any attempted proof for this reason and considered the point to be in any case only of academic interest.

In October 1957, Norman petty took a series of water temperature readings at various places in the cave and reported the results in the “Belfry Bulletin" No 118.  Those of interest to this article are as follows:-

Plantation Swallet Stream

Plantation Stream

Main Stream Dining Room

Pool of Still water in R. Warren

51.0oF.

50.5oF.

48.5oF.

48.5oF

In recording these readings, Norman boldly assumes that Plantation Swallet Stream and Plantation Stream are the same, flowing via Continuation Chamber, but Coase - in commenting on these readings - thought that as the temperature drop was so small, the water could not be the same.

In the following B.B. (No 119 for December 1957) Don again comments on the water temperature readings and mentions that in November 1955, a few readings taken by Roy Bennett again showed the temperature of Plantation Stream to be different from that of the Main Stream.  On this occasion, Plantation Stream was 2.2o colder, presumably because of the air temperature on the surface being lower than the assumed ambient cave temperature of 8.5oF.  His conclusion was still the same, that Plantation Swallet Stream and Plantation Stream were not connected.

At Coase's suggestion, Norman petty and Paul Burt took a further and more comprehensive series of. readings of water temperatures  in December 1957 and the readings were given in the B.B. for January  1958 No 120.  On this occasion, the relevant temperatures were:-

Plantation Swallet Stream

Plantation Stream

St. Cuthbert's Stream

Main Stream in Sewer Passage

45.0oF

47.5oF

46.5oF

48.5oF

A theory was put forward by Petty and Burt as follows.  The surface air temperature was known to have risen considerably shortly before the surface stream temperatures were taken and therefore they proposed that the slower moving St. Cuthbert's Stream had approached nearer to the new air temperature than had the swiftly flowing water of plantation Swallet Stream.  The Main Stream in the cave had risen still further to reach the ambient cave temperature but Plantation Stream - although it had risen - had not reached the cave temperature.  Now, if the source of Plantation Stream was not Plantation Swallet Stream, then it must be  seepage water because there is nothing else on the surface and any seepage water would be at least at the temperature of the St, Cuthbert's Stream, because  it would be even slower moving.  As St. Cuthbert's Stream had reached cave temperature by the time it had become Main Stream at Plantation Junction, seepage water would also have done so.  But Plantation Stream is colder.  Therefore Plantation Stream must be the continuation of the stream entering plantation Swallet. Q.E.D.!

This theory seemed plausible, even reasonable, but there was still no proof of the connection.  Norman and Paul also took samples of the water from Plantation Swallet Stream and from St. Cuthbert’s Stream and chemical analysis showed the former to contain a considerably concentration of chloride ions than the latter.  Their intention was to analyse samples of the water from Main Stream and Plantation Stream in the hope  that a similar difference would be found, thus adding further weight  to their theory.   Unfortunately, it is not known whether these further samples were ever collected and tested because no further reference to them is found in the B.B.

The possible use of accumulative detectors was then realised.  These would 'add together' the  results of  several very small introductions of chemicals, and each of these introductions on their own could thus be  kept well below the minimum level which could cause contamination of the water.  The next episode in the story - as far as is known - was when in May 1958, the present author assisted Chris Falshaw in an attempt to prove the connection that had been hypothesized by Paul Burt and Norman Petty.  In the Caving Log for May 1958 (published in B.B. No 125) will be found a brief account of the setting up of 'instruments' in Plantation Stream and a negative result is implied.  In a later B.B. (No. 128, September 1958) Chris writes a little more about the experiment and explains that it consisted of adding paper maker's Alum to the water at Plantation Swallet and attempting to collect it on an ion exchange column placed in Plantation Stream.  He states that for a variety of (un-named) reasons, the results are suspect.  He mentions also that further water temperature readings had been taken, but gives no figures.

That, then, was the story as obtained from the "Belfry Bulletin" when the author carried out a further experiment during July 1961.  In Volume 3, Number 3 of the "Bulletin of the Bradford Pothole Club” Terry Marston describes a new method of water tracing that has been developed by members of the B.P.C.  Its application to the Plantation Stream problem was immediately seen.  Very briefly, the method consists of adding a very small quantity of dye to the water and collecting it at the other end of the test on specially treated hanks of cotton placed in the water.  The advantages of this method of water tracing over the more usual methods of using fluorescein are numerous.  The dye used is non-injurious to all known fresh water organisms (even the C.R.G. bug, hunters have approved its use) the small quantities required decrease cost and the danger of contamination at the resurgence; the effect is accumulative; and, most important of all, all the possible places for the re-appearance of the dye do not have to be watched continuously for an unknown length of time - one just collects the hanks of cotton at a later date!

The survey showed that Plantation Swallet lay to the East of most of the known cave and therefore the intention was to place cotton detectors in the following streams: Maypole Series; September Series; Continuation Chamber; Tin Mine and Plantation Stream.  However, when the detectors were being placed in position on the 15th July, the party was not capable of this round trip and as a preliminary experiment it was necessary to make do with these sites: Wire Rift; Maypole Stream; Main Stream at the bottom of Everest Passage and also in Sewer Passage; Plantation Stream and the Duck. After leaving the cave, twenty five grams (less than one, ounce) of the dye was added to Plantation Swallet Stream.

The following weekend, the six cotton hanks were removed from the cave and treated to remove the impurities that also stain them, and sometimes mask the dye coloration.  The results were as follows: Maypole Stream; Wire Rift; Main Stream near Everest Passage and Sewer Passage - all negative. Plantation Stream and Duck - both positive.  Therefore it is now possible to state definitely that Plantation Stream does flow from Plantation Swallet and does not have to be classed with the so-called ‘Priddy Green Stream' in Swildons Hole - as a misnomer.  One must be extremely careful in interpreting negative results in water tracing, but as the result was positive at the Duck as well as Plantation Stream (but nowhere else) it seems safe to say that none of the water from Plantation Swallet reaches the Main Stream before Plantation Junction.